


Put Your Arms Around Me

by stardropdream



Category: Voltron: Legendary Defender
Genre: Alpha Keith (Voltron), Alpha/Beta/Omega Dynamics, Anal Fingering, Anal Sex, Bottom Shiro (Voltron), Established Relationship, Galra Keith (Voltron), Knotting, M/M, Multiple Orgasms, Omega Shiro (Voltron), Plot What Plot/Porn Without Plot, Porn with Feelings, Post-Canon, Rutting, Season 8 Doesn't Exist, Size Difference, Size Kink, Top Keith (Voltron)
Language: English
Status: Completed
Published: 2020-02-08
Updated: 2020-02-08
Packaged: 2021-02-28 02:35:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,837
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22616491
Author URL: https://archiveofourown.org/users/stardropdream/pseuds/stardropdream
Summary: There are signs Shiro knows and loves to look for whenever Keith is going into a rut.But his favorite thing about Keith's ruts, by far, is the fact that he getsbigger.
Relationships: Keith/Shiro (Voltron)
Comments: 74
Kudos: 482





	Put Your Arms Around Me

**Author's Note:**

  * For [st00pz](https://archiveofourown.org/users/st00pz/gifts).



> Request fic written for [St00pz](https://twitter.com/curs3dberry), who requested an abo fic with omega Shiro and alpha Keith-- where during his rut, Keith goes full Galra (and gets bigger than Shiro). 
> 
> This fic is based of the art they've done for this AU. Be sure to check them out (and be mindful these are all nsfw): [One](https://twitter.com/curs3dberry/status/1214968084349386753). [Two](https://twitter.com/curs3dberry/status/1176541321957273601), [Three](https://twitter.com/curs3dberry/status/1175461738403090432), [Four](https://twitter.com/curs3dberry/status/1154796977088954369), and [Five](https://twitter.com/curs3dberry/status/1125790207997964289).
> 
> Thank you to [Meg](https://twitter.com/kedawen) for reading this over for me, as always. ♥

“Shiro,” Keith growls in his ear, the sound enough to wake Shiro from the deepest sleep. Whenever Keith’s voice gets deep and husky like this, it sends pleased shivers rippling down Shiro’s spine. 

“I’m sleeping, baby,” Shiro says, more teasing than anything else. He knows that timbre of Keith’s voice well, after all, and he knows that sleeping is out of the question now. 

Keith’s in a rut. 

After years of marriage, even more years since their mating, Shiro knows exactly how Keith’s rut builds— and the five signs he loves to look for. 

The first sign that signals Keith’s growing rut is the way he bites. Keith’s fangs always grow in first and Shiro loves to count the marks on his skin as the days tick closer to the rut, how he can follow the bitten constellation on his skin, all those sucking bruises from Keith’s insistent, teething mouth.

Check that first sign off the list: Keith bites down hard on Shiro’s ear, trying to coax Shiro awake. He growls again, something that’s almost a whine. And Shiro loves to make his alpha whine. 

Shiro stretches luxuriously on their bed and Keith snuffles closer. 

The second sign is the way Keith touches him. Keith is, of course, _always_ touching him, but it’s different when the rut starts burning in his gut. There’s a certain ferocity to it. Keith’s hands drag across Shiro’s skin with purpose. He folds himself around Shiro. He glares at any man who so much as breathes near Shiro. His claws are pinpricks of sensation on Shiro’s chest, blatantly seeking skin-on-skin contact regardless of the location, whether it be out for dinner with their friends or walking down a Garrison hallway. 

Check on that, too. Right now, Keith’s fingers dance over Shiro’s chest as he spoons against him. He gives a pleased trill as he nuzzles Shiro’s neck. 

Keith must know that Shiro’s more than awake now. If he hasn’t already, he’ll undoubtedly smell Shiro’s building pleasure and joy just from this contact. 

The third sign is Keith’s insatiability. Keith’s always had the Galra stamina, but the rut makes it amplify. It leaves Shiro panting and happily exhausted most nights, lying on his stomach, Keith’s come leaking out of him as Keith purrs and nuzzles at the back of his neck, licking their mating mark. He’ll scent Shiro for the entire time his knot is buried inside him. 

Definitely check on the insatiability: with Keith spooned up against Shiro like this, Shiro can feel how hard Keith is, his cock sliding so nicely against the curve of Shiro’s ass. 

The fourth sign is the manifestation of Keith’s Galra traits. The fangs and claws, yes, but the flush of purple to his skin, the stripes that line along his ribs and across his hips. His eyes glowing that familiar yellow in his sclera, present even when Keith is calm and sated, cuddled up in Shiro’s lap like a cat. Shiro’s chest is often criss-crossed with marks from Keith’s claws, dragging over his nipples, down his chest, over his stomach, little crescent punctuations on his hips. 

Keith bites Shiro’s neck with a low whimper. The sound is definitely alpha and definitely Galra. 

“Baby,” Shiro says with a sigh. “How long have you been awake?” 

“ _Forever_ ,” Keith grunts. “Tired of waiting, Shiro…” 

The fifth and last sign is incidentally Shiro’s favorite part: Keith gets _bigger_. 

Shiro likes it most when Keith drapes over him in the morning, like when Shiro makes the coffee or starts their breakfast, and Keith’s noticeably _huge_. Taller, wider, his arms looping easily around Shiro. 

Shiro likes that he’s bigger than Keith, generally. He likes the power Keith holds in his body, how even a tiny alpha can be so strong, so possessive when the mood strikes him. Shiro likes the feeling of covering Keith completely when they’re together in bed. 

But whenever Keith’s rut makes him _grow_ , whenever Shiro wakes in the morning and Keith’s looming above him, shoulders wide, eyes dark with promise— Shiro _loves_ it. 

Nothing can make Shiro fall into an answering heat faster than Keith’s lips tilting into a fanged smile, purring Shiro’s name in benediction. His mate is both Human and Galra, and Shiro loves everything that entails. 

So, a hearty check on the fifth sign, too. Yesterday, when Keith growled at some cadets who glanced over at Shiro, he’d been eye-level with Shiro. Last night, he’d needed to duck to kiss Shiro’s forehead after Shiro said something Keith thought was cute. 

In the time Shiro’s slept, Keith’s bulked up the rest of the way— wider and taller than Shiro, and fully enveloping him in their bed. 

Now that Shiro focuses on it, it’s all he can feel— Keith curled protectively around him, hooking his feet around Shiro’s ankles, his hands pressing against Shiro’s skin. His face buried in Shiro’s hair, lips ghosting the crown of his head. 

It’s always enough to get Shiro slick, his body responding to his mate’s needs. Shiro smiles to himself and wriggles his hips back, grinding against Keith’s growing cock. 

He knows Keith loves the tease of it when Shiro does that, sliding against Keith’s cock, letting him feel the slick as if Shiro’s just daring Keith to enter him— to take what he wants. Shiro hardly needs the prep and he so rarely wants it, not when Keith is like this, not when Shiro just wants to be split open. 

Keith’s hands fondle Shiro’s chest, squeezing his pecs and then drifting down lower over his stomach. Each claw’s point is a kiss against Shiro’s feverish skin. One hand darts down to fist around Shiro’s half-hard cock, stroking. His hands are so big today— massive as they paw over Shiro. Shiro’s large but his cock looks dwarfed against Keith’s palm. Keith’s big fingers squeeze around him, stroking with luxurious attention. 

Shiro sighs, stretching and shoving his hips back to press flush against Keith. He feels Keith’s cock twitch where it’s sandwiched between them. The rumble of a growl coils in Keith’s chest, the vibrations pulsing against where he’s spooned to Shiro’s back. 

“Keith,” Shiro breathes out. 

He turns his head to cast Keith a fond look, but Keith takes advantage of the movement to instead swoop in to kiss Shiro. It’s a stinging kiss, just on the edge of brutal as he sucks on Shiro’s bottom lip and pulls him in closer.

Shiro indulges the kiss, letting Keith deepen it with a hungry swipe of his tongue. Shiro doesn’t try to muffle his smile and it seems to please Keith, if the thunder of a purr in his chest is any indication. He presses closer to Shiro, nails scraping at his chest as Keith digs in, possessive and protective. 

“Baby,” Shiro says when he finally breaks the kiss, apologizing for the sudden absence with one quick peck to Keith’s pouting mouth. “You could have woken me up earlier if you needed me.” 

“You smell good,” Keith says, voice grumbly. It’s cute. He buries his face into Shiro’s bed-rumpled hair, inhaling deep enough that his chest swells. That’s cute, too. “Just wanted to smell you.” 

“You know what will make me smell better,” Shiro teases. He knows how much Keith loves to make Shiro just smell like _him_. Like mate, like alpha, like come and sex and love. 

Keith purrs at the thought, a satisfied sound, and nuzzles at Shiro’s jaw. Shiro hums, tipping his head back to expose his throat. It earns a pleased trill from his mate, who nips gently at the long column of his neck. 

Keith’s hardly senseless when he’s like this, just handsy. Typical Keith-in-a-Rut. 

Shiro knows how _he_ gets during his heats— needy, clingy, a primal need within him demanding to care for Keith. He knows it’s a similar pull for Keith, too, that coiling need to leave his marks all over Shiro. It’s never enough to actually disrupt their day— only a mild annoyance if the rut comes in while they’re still working— but there’s a certain indulgence to waking in the morning and knowing that he’ll spend the whole day satisfying his mate, keeping him locked in here until the rut passes. 

Shiro will need to send a call to the Garrison and to the Paladins to let them know they’ll be otherwise occupied today. But his PADD is plugged into the wall outlet on the other side of the room and Shiro knows that Keith’s not about to let him get up to fetch it. 

As if Keith might sense the very thought, his fangs drag up Shiro’s jaw. He whines low and throaty for his mate. Shiro breathes out and curls his arm back, running his hand up Keith’s flank in greeting, crooning out a breathy, inviting sound, something purely omega and unembarrassed about it. He knows how much Keith likes to be invited. 

“Sweetheart,” Shiro coos. “Mate. Alpha. _Keith,_ I’m here.” 

Keith’s big hands cup Shiro’s body, maneuvering him around until Shiro’s lying flat on his belly and Keith’s pressing down against him. Keith’s hips shift back and that’s the only warning Shiro gets before there are fingers inside him. They slide in so easy, Shiro’s body open for a rutting alpha. _His_ alpha. Shiro sighs at the thick spread of Keith’s fingers. 

He feels pinned down in the best way, Keith’s sure hands anchoring him in place. 

Keith gives a happy grumble as he touches Shiro, curling around him to engulf him completely. He ducks his head, burying his face against the crown of Shiro’s head, inhaling his scent. His chest swells with it, pushing Shiro down into the mattress. 

“I don’t need the prep,” Shiro says and there’s the tiniest hint of a whine to his voice that makes Keith chuckle and twist his fingers up pointedly. 

“Like it,” Keith grunts. 

Really, Keith’s not prepping him at all. He’s teasing him. He slides his fingers inside Shiro, barely spreading or dragging his thumb across his rim. They sit inside him, curling and seemingly satisfied with Shiro’s slick dripping down to Keith’s knuckles. Shiro knows Keith likes the feeling of it, likes to lick his fingers clean once he’s finished because it makes Shiro flush with longing. 

“Want to fuck you,” Keith says with a low sigh, fingers crooking a little, dragging and tugging at Shiro’s rim. 

Shiro hums, squirming down against Keith’s hand— it’s hardly enough. “Well. What’s stopping you?” 

Keith whines low in his throat, shifting down enough to lick the mating mark at the back of Shiro’s neck. He’s Shiro’s shadow like this, massive and constricting, and Shiro wonders if this is how Keith feels normally with Shiro draped over his back. 

Keith bites down on the mark. It sends pleasure rippling through Shiro, building and igniting in his gut. He’s wet, dripping around Keith’s fingers, and nothing gets him wetter than that searing kiss Keith plants against the back of his neck.

Shiro shivers, the whine in his throat matching Keith’s. Keith twists his fingers and the pleasure makes Shiro arch. He catches his bottom lip between his teeth, biting back a low, contented moan. He wriggles his hips back against Keith’s fingers, as if that might prompt him to move deeper, faster, harder. 

Keith does none of those things. He drags his teeth over Shiro’s sleep-warmed skin and follows the arch of his spine. Shiro sighs as he wriggles beneath him. 

He pushes Keith’s fingers away and they slide out of him with slicked ease. With enough space now, Shiro gets his legs under him and pushes his hips back— presenting himself to his alpha. 

He hears Keith suck in a sharp breath, his growl low and nearly inaudible. 

Shiro knows Keith goes weak whenever Shiro presents. He knows Keith can’t resist the sight of slick dripping down his mate’s legs, his hole open and ready for Keith. Most of all, Shiro knows that Keith can’t resist the smell of him or the way he can make his voice pitch low and welcoming. 

Like now. “Come on, beautiful,” Shiro says, inviting. “Come here. Come to me. You know I’ve got you.” 

Keith slumps against him, biting at his neck and shoulder, the sting trailed by the softest pillow of Keith’s lips. Shiro shivers in Keith’s hold, comforted by the familiar, tight coil of Keith’s arms around him. 

Keith stretches to his full height, draped and curled around Shiro, blocking out the early morning light. It’s only Keith around him— his hair falling to kiss Shiro’s shoulder, one clawed hand digging into the mattress, palm covering Shiro’s, the other flat against the full expanse of Shiro’s stomach. 

Shiro holds them up, arms quaking with the delightful weight of his husband against him. Keith’s massive fingers slide between Shiro’s splayed ones, pinning his hand down against the mattress. 

The first thrust of Keith’s hips is always fast. Even with multiple rounds in the days leading up to a rut, Keith is impatient and pent-up. He grunts now, shoving his hips against Shiro’s ass. He only needs to swivel his hips a little to get his ruddy cockhead to catch on Shiro’s hole. Keith teases at the rim before he slides home.

Shiro keens softly, pleased, and wriggles his hips back. “Yes, Keith.” 

Keith is relentless after that. He fucks into Shiro, his hold brutal and possessive as he ruts into Shiro. Shiro lets him take what he needs. The first time is always just to take the edge off; he knows Keith will take his time with him the times after that, the second, the third, the fourth— his mate needs several rounds to exhaust himself. 

“Baby,” Shiro sighs as Keith hunches down to suck a mark on his shoulder. Shiro squirms beneath Keith, trying to ease his cock in deeper, to coax the swelling knot past his rim. “Keith—” 

Keith garbles out something guttural and primal, unwilling to pull back from Shiro’s shoulder. He rocks his hips forward once to satiate Shiro, but otherwise seems content to bite and suck over Shiro’s flushed skin. 

Sometimes Shiro wishes the stereotypes about alphas were true— about them getting lost in a rut, just fucking with abandon and without thought. But even deep in his rut, Keith is only ever attentive to Shiro. If the rut is about primal needs, Shiro can’t be surprised that Keith hyper-focuses on Shiro. 

“You can be rough,” Shiro offers. 

“Want to feel you,” Keith says in response, which is neither agreement nor disagreement to Shiro’s suggestion.

Shiro sighs and rolls his hips back. “You can feel me all you want, Keith.” 

Keith bites Shiro’s neck and then presses his lips there in a lingering kiss. He licks the long column of Shiro’s neck. “Mine.”

“Yeah, Keith,” Shiro breathes, feeling the knot pushing against this rim. He bites his lip, eager for it. 

Keith is a pleasant weight against him, massive and leaving Shiro feeling small. The hand that curls down Shiro’s front and twists over his cock is huge, thumbing at his slit and then corkscrewing down, working him towards the edge of orgasm. Shiro ducks his head, watching his cock disappearing into that fist. 

Shiro’s helpless against it, mouth falling open as he moans, thrusting his hips back to meet Keith’s cock, the swell of it inside him. 

Keith bites down hard on Shiro’s shoulder, just on the edge of breaking skin and Shiro’s gasp is a hitching, needy thing— pure omega to its core. The effect it has on Keith is no different: he loses the pace of his hips when he hears the sound. He poises himself above Shiro, grunting low, and then slamming his hips forward. 

He fucks into Shiro, relentless and brutal as he strokes inside Shiro. Shiro’s so slick, so open for him, all he can focus on is the stretch of him, of that knot at the base of his cock, just waiting to plug Shiro. He wants to be plugged again and again. 

A drop of sweat drips down the slope of Shiro’s nose, beading at the tip. When Shiro ducks his head, moaning, it falls away. It’s primal, the way Keith holds him, how easily he could bend Shiro in half. 

And when he comes, when he fills Shiro, when the knot finally pushes in, Shiro can only cry out. Keith fucks his hand over his cock until Shiro comes in pulses, making Keith’s fingers slick and shiny with his come. 

He whimpers when Keith bites his neck, licking up the column of it and scenting him, covering Shiro in just the smell of Keith. It’s just how Shiro likes it. He feels all shaky and fucked-out and it’s only the first round. 

Keith’s fingers fist in Shiro’s hair, forcing his head back, exposing his throat. Shiro moans again as Keith licks and nips the curve of his neck, leaving biting kisses in his wake. His hair’s wild and unruly, falling in his shining yellow eyes. The fangs are glinting now, his ears pointed. Full rut now, and full Galra. 

Shiro coos quietly, smoothing his hand over the arm curled around him, arching his back so Keith can attack his skin with all his teeth. Keith responds to it with a pleased breath, his hand grabbing at Shiro’s, threading them together even as he pins Shiro’s down, holding him in position as he shimmies his hips forward, working the knot in deeper. 

Shiro sighs out, blissful. “Fuck, I love it when you rut.” 

Keith grunts, but Shiro feels his smile against the sensitive junction between neck and jaw. “Yeah.” 

Shiro loves the throaty way Keith speaks during his rut— still cognizant, still himself, but a deeper, rustier sound. It makes desire pool thick in Shiro’s gut. His cock stirs where it’s pressed down against the mattress and he knows it won’t take him long to get hard again, especially once Keith’s knot goes down and he, inevitably, fucks Shiro again. They still have a few minutes left before then, though. 

“And I love _you,_ ” Shiro adds.

Keith chuffs a breath. “Yeah.” 

Shiro turns his head and bites Keith’s bottom lip, dragging him in close enough to suck his tongue into his mouth and then kiss him sloppily. When they part, it’s just so Shiro can bring Keith’s fingers to his mouth, licking away his own come and slick from each fingertip. 

“Gonna fill you,” Keith grunts. 

“Yeah, Keith,” Shiro says, breathless. 

When Keith’s knot goes down, he’s efficient in the way he slips out of Shiro— cringing only because Shiro can’t hold back his needy whine at the feeling of _empty_ — and then grabs at Shiro. His nails dig tight into Shiro’s thighs, and he drags him down the bed and flips him over. The movements are effortless, and it leaves Shiro breathless, sprawled on his back and staring up at his husband. 

Keith towers above him, caging him in. His eyes are glowing yellow, the slit pupils needled enough that they’re nearly invisible. His hair is a dark corona against the morning sunlight, his body flushed a deep purple. 

“Keith,” Shiro says, just for the sake of saying his name— he loves Keith like this, loves that he’s the only one that can satisfy him, the only one Keith can trust with this, to see him like this. Even before they were mated, long before they were married, it was always this way. 

Keith’s palm cups Shiro’s cheek, the other resting against his chest, fingertips just ghosting against Shiro’s throat. 

Shiro peers up at Keith, who watches the slow drag of his thumb over Shiro’s bottom lip as he stares down at Shiro with undisguised hunger. 

Shiro loves that look. But then again, he loves everything about Keith. He bites his lip, smiling as he leans into the touch at his cheek. 

“Mate,” Keith whispers. 

“Mmmhmm,” Shiro hums, pleased. His voice comes out more breathless than he means it to when he says, “That’s me, baby.” 

He likes the way Keith’s chest puffs up with pride at the agreement. His hands sweep over Shiro, petting him, tracing over every single mark he’s left across Shiro’s shoulders and neck. 

God, but really, Shiro just loves everything about Keith. Every inch of him. Every side of him. 

He moans Keith’s name when Keith fucks into him again, spreading his legs wide effortlessly, his hands gripping the backs of Shiro’s thighs. He’s a satisfying weight pressing down on Shiro as he thrusts into him, his cock so big, so deep inside him. Shiro’s already so wet, so filled, and it’s blissful— more. He always wants more. He wants everything that Keith can give him. 

Keith strokes into him, bending Shiro nearly in half. He grunts and growls, his fangs sharp even as he grins down at Shiro, fueled on by Shiro’s obvious pleasure— and really, that’ll always make Shiro’s heart feel heavy, knowing that even in the midst of a rut, Keith’s priority and focus is always, always Shiro’s happiness. 

The hand on his cock is testament to that. Keith loses his pacing in favor of stroking Shiro off. And Shiro comes with a cry as Keith squeezes around him. He squeezes around the cock inside him in turn, milking Keith in deeper. 

Keith is massive around him, blotting out the soft morning light, flooding Shiro’s vision. His big hands on his body, his thick cock inside him. Every inch of him only Keith’s. 

When Keith knots him again, it’s heavenly— Shiro feels Keith fill him, plugging him up, and he’s slick and sweaty and needy, and it’s everything. 

Keith growls at him, ducking his head to bite at Shiro’s collarbone, content to leave marks over his chest now that he can reach it. Shiro closes his eyes, just letting himself feel the way Keith touches him, with hands, with teeth, with tongue, with lips. 

It takes a few minutes before Keith can speak again. He snuffles at Shiro’s throat, working his way up with little licks and kisses, whimpering a little as he scents Shiro. 

Shiro nuzzles back indulgently, feeling sated and full and _perfect._ He loops his legs and arms around Keith, clinging to his massive form and letting himself feel blissfully, perfectly small. Keith holds him close obediently, cradling him. 

“Shiro,” Keith says against his adam’s apple, licking around the swell of it. Shiro hums just so Keith will feel the vibrations up his throat.

His answer is Keith’s answering purr, pressing down hard against Shiro’s chest. 

Keith draws back to blink at him, lazy and catlike, and then he smiles. “Good morning.” 

Shiro snorts a laugh, fingers petting up into Keith’s hair and curling tight, cupping the back of his head as he beams up at him. 

“Morning, Keith.” He grins, wicked and teasing. He wriggles his hips around the knot still plugging him tight. “Feeling better?”

“I’m just getting started,” Keith promises and Shiro knows that’s true, arching with a pleased breath as Keith scoops him up and kisses him.

**Author's Note:**

> This story is part of the [LLF Comment Project](https://longlivefeedback.tumblr.com/llfcommentproject) (including the [LLF Comment Builder](https://longlivefeedback.tumblr.com/commentbuilder)), which was created to improve communication between readers and authors. This author invites and appreciates responses, including:
> 
>   * Short comments
>   * Long comments
>   * Questions
>   * “<3” as extra kudos
>   * Reader-reader interaction
> 

> 
> This author replies to comments.
> 
> [Twitter](https://twitter.com/stardropdream)


End file.
